test log func for swallowing command output

tests/testutil.sh

@@ -11,6 +11,12 @@ accounts=$(curl -s http://localhost:1317/cosmos/auth/v1beta1/accounts | jq -M ".
 declare -g ALICE=$(echo $accounts | jq -rM '.[] | select(.account_number == "0") | .address')
 declare -g BOB=$(echo $accounts | jq -rM '.[] | select(.account_number == "1") | .address')
 
+function swallow {
+    read -r out
+    log_ok
+    echo $1 + swallow error
+}
+
 function assert_eq {
     read -r out
     if [[ $out = $1 ]]; then